The purpose of this proposal is to provide Dr. Mrug, the applicant, with new training in substance use research and advanced statistical modeling to develop her career as an independent investigator in the area of adolescent substance use and abuse. The ultimate career goal of the applicant is to develop preventive interventions tailored to specific subgroups of youth. Consistent with this long-term goal, the proposed research program focuses on the role of gender and ethnicity in initiation of substance use in preadolescent and early adolescent populations. Specifically, we seek to 1) describe gender and ethnic differences in preadolescent and early adolescent use of alcohol, tobacco, marijuana, and inhalants;2) examine specific parenting practices as mediators of these gender and ethnic differences;3) identify the impact of neighborhood context on parenting and substance use in preadolescence and early adolescence;and 4) examine whether early initiation of substance use represents higher risk for future substance-related and Functional outcomes in specific gender and ethnic subgroups. This research will provide important insights into the role of gender and ethnicity in early substance use and provide useful information for developing tailored preventive interventions for girls and boys of different ethnicities. The K01 award would provide the applicant with the skills and mentoring necessary to carry out the proposed research and allow her to fully focus on developing the research program. Proposed training activities include a structured 4-year program of individual mentoring, coursework, and supervised research under the direction of senior mentors in the areas of adolescent substance use (Dr. Windle), advanced statistical methods (Dr. Roth), and contextual influences on adolescent risk behavior (Dr. Bolland), as well as additional training in the responsible conduct of research. To accomplish the specific aims of this proposal, Dr. Mrug will conduct secondary data analyses of two data sets (Healthy Passages and Birmingham Youth Violence Study) and collect follow-up data on participants in the Birmingham Youth Violence Study. In addition to publication and conference presentation of empirical findings, Dr. Mrug will write and submit an independent research grant (R01) in later stages of this award.